Ion exchange softening: effects on metal concentrations

Leaching data from a two‐phase study indicate that ion exchange softening does not systematically increase metal concentrations. A corrosion control pipe loop study was conducted to evaluate the effect of ion exchange water softening on metal leaching from household plumbing materials. The two water sources evaluated had different pH values and hardness levels. Results showed that removing hardness ions with a household water softener did not lead to a pattern of higher metal leaching from various home plumbing materials containing lead, copper, and zinc. Furthermore, the water softener did not have a detrimental effect on several significant water quality parameters that influence metallic solubility and the rate of corrosion, i.e., pH, total inorganic carbon, dissolved oxygen, chlorine, temperature, and orthophosphate.